The over-all objective is to further our understanding of the cellular and biochemical bases of corneal ulceration so that it will be possible to prevent loss of vision. Cell and tissue culture methods will be used to study the role of the plasminogen activator-plasmin system in the chemotaxis of polymorphonuclear leukocytes and in the activation of latent corneal collagenase. Cell culture will be used to obtain latent collagenase that will be purified to homogeneity. Methods of protein chemistry will be used to study the mechanisms of activation of the latent enzyme. Specific antiserum to the enzyme will be raised and will be used to localize collagenase during ulceration in model systems. In vitro "coupled" systems will be developed to study the synthesis, secretion, activation, and clearance of corneal collagenase. The role of progestational hormones in regulating collagenase in herpetic stromal keratitis will be investigated.